/*
 * Copyright (c) 2012 Jason Polites
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.bupt.library.pinch2zoom;

/**
 * @author Jason Polites
 */
public class FlingAnimation implements Animation {

    private float velocityX;
    private float velocityY;

    private float factor = 0.85f;

    private float threshold = 10;

    private FlingAnimationListener listener;

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.polites.android.Transformer#update(com.polites.android.GestureImageView
     * , long)
     */
    @Override
    public boolean update(GestureImageView view, long time) {
        float seconds = (float) time / 1000.0f;

        float dx = velocityX * seconds;
        float dy = velocityY * seconds;

        velocityX *= factor;
        velocityY *= factor;

        boolean active = (Math.abs(velocityX) > threshold && Math.abs(velocityY) > threshold);

        if (listener != null) {
            listener.onMove(dx, dy);

            if (!active) {
                listener.onComplete();
            }
        }

        return active;
    }

    public void setVelocityX(float velocityX) {
        this.velocityX = velocityX;
    }

    public void setVelocityY(float velocityY) {
        this.velocityY = velocityY;
    }

    public void setFactor(float factor) {
        this.factor = factor;
    }

    public void setListener(FlingAnimationListener listener) {
        this.listener = listener;
    }
}
